Clinical_Rounds_in_Endocrinology_Volume_II_-_Pediatric_Endocrinology

383

type 3). Recently, type 4 MEN syndrome has also been described. This classi-

fication is based on involvement of specific endocrine organs in each particular

type of MEN syndrome. The disorders which are associated with multiple

endocrine as well as non-endocrine neoplasia like Carney’s complex, Von

Hippel–Lindau disease, and neurofibromatosis type 1 are classified under mul-

tiple endocrine and other organ neoplasia (MEON) syndrome.

3. What are the endocrine organs involved in different MEN syndrome?

The endocrine organs involved in different MEN syndrome are summarized in

the table given below.

MEN syndrome Endocrine organs involved Associated features

MEN 1 Parathyroid: hyperplasia/

adenoma

Lipoma, collagenoma,

angiofibroma, gastric carcinoid,

Pituitary: prolactinoma, meningioma

somatotropinoma

Pancreas: gastrinoma,

insulinoma

Adrenal: nonfunctional

adrenal hyperplasia and

adenoma

Thyroid: thyroid nodule,

MNG

MEN 2A Thyroid: MTC Cutaneous lichen amyloidosis

Parathyroid: hyperplasia/

adenoma

Hirschsprung disease

Adrenal: pheochromocytoma

MEN 2B (MEN3) Thyroid: MTC Mucosal neuroma, marfanoid

habitus, and slipped capital femoral

epiphysis

Adrenal: pheochromocytoma

MEN 4 Parathyroid: adenoma Reproductive organ neoplasia

Pituitary: adenoma

Pancreas: NET

MNG multinodular goiter, MTC medullary thyroid carcinoma, NET neuroendocrine tumor

4. What is the prevalence of different endocrine organ involvement in MEN1?

Parathyroid gland is the most common endocrine organ involved, and parathy-

roid hyperplasia/adenoma is seen in 95 % of patients with MEN1 syndrome.

Pancreatic neuroendocrine tumors (NET) occur in 40–70 % of MEN1 patients

and comprise of gastrinoma (40 %), insulinoma (10 %), glucagonoma (<1 %),

vasoactive intestinal polypeptidoma (VIPoma, <1 %), and nonfunctioning NET

(20–55 %). Anterior pituitary tumors occur in 30–40 % of patients of MEN 1

and consists of prolactinoma (20 %), somatotropinoma (10 %), corticotropi-

noma (<5 %), and NFPA (<5 %). In addition, patients with MEN1 may develop

adrenocortical tumor (40 %), angiofibroma (85 %), lipoma (30 %), collagenoma

11 Multiple Endocrine Neoplasia